Shock-absorber.



J. S- LANG. suocx ABSORBER.

APPLICATON HLED NOV. 29, 1915.

1,269,289. Patented June 11, 1918.

4 SHEETSSHEET l- Patented June 11, 19l8.

4 SHkETSSHEET 2.

3 Fww L S. LANG.

SHOCK ABSORBER.

APPLQCATION FILED NOV,29.19I5.

I. S. LANG.

SHOCK ABSORBER.

APPLlCAHUN FILED NOV. 29. m5

Patented June 11, 1918.

4 SHEETS SHEET 4 MM w JAMES S. LANG, OF BOSTON, MASSACHUSETTS.

SHOCK-ABSORBER.

Specification of Letters Patent.

Patented June 11, 1918.

Application filed November 29, 1915. Serial No. 88,945.

To all whom it may concern:

Be it known that I, JAMES S. LANG, of Boston, in the county of Suflolkand State of Massachusetts, a citizen of the United States, haveinvented a new and useful Improvement in Shock-Absorbers, of which thefollowin is a full, clear, and exact description, re erence being had tothe accompanying drawings, farming a part of this specification, inexplaining its nature.

The present invention relates to'shock absorbers that are especialldesigned to be used on automobiles or at er vehicles.

Among the objects of my invention is to provide a nick-acting andflexible device which shall e positive in its operation and be properlyoperative even where but a limited space and range of movement areavailable.

The shock absorber embodying my invention is of that type which dependsfor its action upon the frictional engagement or lack of such engagementbetween certain operating parts consisting in the resent instance of ablade or blades and riction shoes engaging the blades.

The manner in which the basic elements of the device are combined andcontrolled in order to attain the ob'ects above referred to can best beseen an understood by reference to the drawings, in which Figure 1 is aside elevation of a shock absorber embodying my invention.

Fig. 2 is a side elevation the same as Fig. 1 excepting that theoperating parts are shown in a slightly changed operative position.

Fig. 3 is a front elevation of the device.

Fig. 4 is a longitudinal vertical section of the device as shown in Fig.1.

Fig. 5 is a longitudinal vertical section of the device as shown inFig.- 2.

Fig. 6 is a longitudinal vertical section substantially the same as Fig.5 excepting that the basic parts of the blades and friction shoes are inengagement with one another at a point different from that shown in Fig.5. This figuretogether with Figs. 4 and 5 are illustrative of theoperation of the device as will later be explained.

Fig. 7 is a horizontal cross section of the device.

Figs. 8 and 9 show, res ectively, in plan and in side elevation one ofthe working elements of the device and Fig. 10 is a view in perspectiveof another of the workin elements of the device.

Fig. 8 is a plan of one of the working elements of the device.

Fig. 9 is a. view in perspective of another of the working elements ofthe device.

Figs. 10 and 11 show, respectively, in section a slightly modified formof construction to which special reference will hereinafter be made.

1 is the friction blade. This is preferably made in two sections 2 and2'. The sections of the blade have the general form of elongated latesand are made of steel or other suita le material. The blade section 2has preferably the same uniform thickness throughout its length, whilethe section 2' is tapered, that is, made with a gradually increasingthickness from its inner toward its outer end. The blade sections areprovided each with an outer attachable end 3.

Engaging the blade sections 2 and 2 are friction shoes 4, 5 and 6. Ofthese shoes the shoe 5 lies between the blade sections and engages theinside faces thereof. The shoes 4 and 6 are arranged outside thesections and engage their outer faces respectively. As will be morefully explained, the blade and shoes are movable relatively to oneanother and it is the frictional engagement of the shoes with the bladewhich furnishes the retarding influence upon the vehicle spring withwhich the device is used. Each of the shoes 4, 5 havebodies of agenerally rectangular shape with a width equal to that of the blade. Theshoes are associated or nested together in their relationship to oneanother and to the blade as follows:-

- The shoe 4 is provided at either side with spaced flanges 7 and 8 (seeFig. 1). These flanges lap by the side edges of the blade section 2against which the shoe has bearing. The shoe 5 is (provided on eitherside with similarly space flanges 9 and 10 which are extended or widenedto lap by the side edges of both the blade sections 2 and 2 betweenwhich the shoe lies. The shoe 6 is provided with a flange 11 at eitherside. These flanges roject laterally beyond the sides of the b adesection 2 and are rovided with right-angularly-disposed 0 sets 12 whichextend by the sides of the blade sections 2 and 2 and the shoes 4 and 5and between the respective sets of flan es 7, 8, 9 10 of these shoes(see Fig. 1). T us associated, the relation of the friction shoes to oneanother and to the blade is such that the shoes are jointly retained toslide lon itudinally in either direction 'along t e blade. The shoes 4and 6, however, are permitted to have a motion of translation withrelation to the faces of the blade by which the intensity of theirpressure and that of the shoe 5 against the faces of the blades may beincreased or allowed to diminish as will later be explained.

The friction shoes are otherwise supported and retained by a carrier 14and other parts coiiperating with it. The carrier 14 comprises a casinor housing of which 15 represents its bo y which is provided with anattaching bar extension 16. The body of the carrier is arranged to liealongside the blade outside the shoe 6 and spaced from it in order toprovide for the interposition of the roller bearings 17 to which specialreference will later be made. From the body 15 of the carrier thereproject sides 18. These sides lie in substantially the same planes asthose occupied by the flanges on the sides of the friction shoes. Thesides 18 extend from the back or body of the carrier to the shoes 6 fromwhich point they'lex tend by the side edges of the friction ade byportions 19 and 20 lying respectively above and below the flanges on thesides of the friction shoes. The extending portions 19 and 20 of thesides 18 present interior edge portions 21 and 22, respectively, whichface the flanges on the friction shoes and provide stops with whichthese flanges have engagement. The edge portions 21 and 22 are separatedfrom one another a distance permitting of the shoes bein movable for alimited distance in reverse irections along the blade independently ofthe carrier, or, vice versa, ermittin of the carrier being longitudinaly movab c with a limited movement independently of the friction shoes,the movement in either case being limited by the engagement of theflanges on the sides of the shoes with the edges 21 and 22 on the sidesof the carrier;

Coiiperating with the carrier in its retention and control of thefriction shoes is a U- shaped strap comprising two threaded arms orbolts 25 and connection 26 between them. The connection 26 lies within asocket 27 formed upon the back of the body of the carrier, theadaptation being such that the connection may turn within this socketand the bolts 25 turn with it upon an axis at substantially right anglesto the longitudinal line of the blade. The strap arms 25 extend fromtheir connection 26 by the side 18 of the carrier and thence forwardbeyond the friction shoes where their projecting ends are retained asfollows: The friction shoe 4 is incised upon the rear side thereof toform a central projecting semi-circular bearin 28. Upon this bearin ismounted a saddle aving a body 29, the caring 28 fittin within a socket30 formed centrally wit in the body of the saddle. The body of thesaddle is made substantially wedgeshaped whereb it may enter theincision on the rear side 0 the shoe 4 and be enabled to turn freelyupon the bearing 28. The body of the saddle is extended outwardly ateither side, the extensions therefrom being provided with forked. ends31, each end presenting on its inner side a bearing 32 (see Fig. 7). ()nits outer side the saddle presents raised rib portions 33 arranged uponeither side of the median line of the saddle. The respective threadedends of the strap arms 25 extend through the forked ends 31 of thesaddle. Arranged outside the saddle and bearing against it is a curvedspring 35 having in it slots 36 through which the ends of the strap armsalso extend. The slots 36 formed in the spring are such that when thespring is in engagement with the saddle the ribs 33 on the outer side ofthe saddle will enter the slots 36 in the spring, thereby operating tocenter and otherwise hold the spring in proper relation to the saddle.Arranged outside the spring 35 is a plate forming a keeper 38 throu hwhich the ends of the strap arms exten and are secured by nuts 39arranged upon the threaded ends of the arms and bearing against thekeeper. Attention is also directed to the nuts 40 adjustable upon thestrap arms 25 to have engagement with the bearings 32 on the inner sidesof the forked ends of the saddle for purposes which will later beexplained.

As before described, there is interposed between the body 15 of thecarrier and the friction shoe 6 roller bearings 17. The general form ofthese bearings is shown in Fig. 10 where it will be seen that thebearing comprises a body 42 having the form of a plate substantially eual in len h to the width of the blade. he side e ges of the body of theplate are thickened or widened to form heads 43, each presenting arounding bearing surface 44. Two of these roller bearings are preferablyemployed and the heads thereof are contained within sockets 47, 48, thesockets 47 lying on the outer side of the shoe 6 and the sockets 48 onthe inner side of the body of the carrier, the respective sets ofsockets facing one another. The surfaces 44 of the bearings engage,respectively,

the surfaces 50 and 51 of the sockets, the surfaces 50 being upon theshoe 6 and the surfaces 51 upon the body of the carrier, thesesurfacesforming the bottoms of the sockets. The surfaces 50 and 51 ofthe sockets are substantially parallel surfaces oppositely arranged buteach having a slight angular inclination to the longitudinal line of theblade. In other words, each of the res ective sets of surfaces 50 and 51have a slight outward inclination from the longitudinal line of theblade in the direction of the inner ends thereof. With the surfaces thusinclined, if the friction shoe 6 and carrier be moved relatively to oneanother on lines substantially parallel with the longitudinal line ofthe blade, then the space will vary between the surfaces 50 and 51.along a line drawn through these surfaces at substantially right anglesto the longitudinal line of the blade, the space being longer when theshoe 6 and body of the carrier are moved to the position shown in Fig. 4where that portion of the surface 50 nearest the blade is in oppositionto that portion of the surface 51 farthest from the line of the bladesand the distance will be shorter when the shoe 6 and carrier are in theposition shown in Fig. 5 where the portion of the surface 50 farthestfrom the line of the blades is in opposition to that portion of thesurface 51 nearest the line of the blade.

Each roller bearing 17 is interposed between the sockets 47, 48 with theheads of the bearings contained within the sockets and the roundingsurfaces 44 of the heads bearing, respectively, against the surfaces 50,51 of the sockets. When the shoe 6 (and the other shoes with it) ismoved into the position relatively to the carrier shown in Fig. 4, thenthe surfaces 44 of the roller bearings will engage, respectively, thoseopposing portions of the respective surfaces 50, 51 which lie farthestapart. When, however, the shoe 6 (and the other shoes with it) is movedinto the position relatively to the carrier shown in Fig. 5, then thesurfaces 44 of the roller hearing will engage, respectively, thoseopposing portions of the surfaces 50, 51 of the sockets which lienearest together. Now the space occupied by the respective bearings whenin engagement with any part of the surfaces 50, 51 remains constantowing to the circular form of the bearings, the surfaces 44, in otherwords, if continued forming a complete circle. The effect is that as thecarrier is moved from a position relatively to the shoe 6 (and othershoes with it) as shown in Fig. 4, to the relative position shown inFig. 5 the roller bearings will operate to gradually separate the backof the carrier from the shoe 6 which has the effect, through the strapwhich encircles the back of the carrier, to compress the spring 35,which accordingly operates in part, through the roller bearings andtheir connecting parts, to press the friction shoes against the blade,the pressure increasing gradually and constantly until the carrier andshoes have reached the relative position shown in Fig. 5 as aboveoutlined.

The essential advantage or advantagesv residing in such an arrangementis as follows: In the first place the angle of thrust of the rollerbearings'when exerting pressure through the influence of the springremains substantially constant and this angle is less than the criticalfriction angle. In other words, the angle between the line of thrust ofeach bearing and the line normal to the blade is less than the criticalfriction angle.

By critical angle is meant the angle between the line of thrust of thebearing and a line normal to the blade, if the hearing was so inclinedto the normal that the force exerted by it would cause the frictionshoes to slip alon the blade instead of exertingl the desire frictiongrip. According to t e construction shown not only is the angle ofthrust of the roller bearing substantially constant, but it is also wellwithin the critical angle, eliminating any possibilitgl of slippage.

A rther advantage of the construction shown resides in the fact that thepressure exerted upon the shoes becomes gradually and evenly increasedfrom the time when the parts are in the position shown in Fig. 4 to thetime when the arts have been moved into the position s own in Fig. 5, amaximum of pressure then being exerted upon the shoes.

In Figs. 10 and 11 there is shown a slight modification of theconstnuction last referred to in that the surfaces 52, 53 of the bottomsof the respective sockets within which the roller bearings arecontained, are surfaces substantially parallel with one another and withthe longitudinal line of the blades instead of being inclined withrelation to the line of the blades as are the surfaces 50, 51 beforedescribed, and in place of employing a circular roller bearing there isemployed an elliptical roller bearing. In other words, the heads of theroller bearings are formed to present exterior elliptical surfaces 55which surfaces were they extended to merge with one another would form acomplete ellipse.

Owing to its elliptical form, the diameter of the bearing is variable,that is, the diameter along which pressure is being transmitted. Whenthe relative positions of the shoes and carrier are as shown in Fig. 4,then the present hearings will be exerting pressure along the lines ofone of their esser diameters and, as the arts are moved into theposition shown in ig. 5, pressure will be exerted along the lines ofdiameters of gradually increasin length due to the elliptical form ofthe aring, thereby effecting a mode of o eration substantially the sameas the roller earing first described.

This type of roller hearing has also the same advantages as before, viz:the angle of thrust of the bearing remains substantially constant andlies well within the critical angle. The pressure exerted by thebearings is a gradual and uniformly increasing pressure, the same asbefore.

In accordance with the operation of the parts, as will later be referredto, the osition of the shoe 6 (and other shoes wit it) in relation tothe carrier, as shown in Fig. 4, may be referred to as their ino erativeposition and which is defined by the caring of the flanges of thefriction shoes against the edge 22 of the sides of the carrier; whilethe relative position of the friction shoe 6 (and other shoes with it)in relation to the carrier, as shown in Fig. 5, may be referred to astheir operative position which is defined by the bearing of the flangesof the friction shoes against the top edge 21 of the sides of thecarrier.

The friction shoes are maintained in a normally operative position bythe interposition of a coiled spring 56 between the under side of thefriction shoe 6, or that side facing the inner end of the blade, andthat portion 54 of the carrier which lies opposite the same. The spring56 is held in place by butts 57 formed respectively on the under side ofthe shoe 6 and the portion 54 of the carrier, these butts entering thecoils of the spring and holdin it securely in place.

In the application 0 the present device I prefer that the blades besecured at their inner ends 3 to the spring which connects with the bodyof the vehicle or to the body of the vehicle directly by any suitablefastening (not shown) and that the attachable bar extension 16 of thecarrier for the friction shoes be secured either to the spring whichconnects with the axle of the vehicle or to the axle directly by anysuitable fastening (not shown).

The operation of the device is as follows The normal arrangement of theparts of the device is as shown in Fig. 4 and corresponds with thenormal osition of the vehicle spring with which t e device isassociated. It will be seen that the friction shoes at this time arethrown into an operative position with relation to their carrier and theU-shaped strap into an acute angular position with relation to a linenormal to the blade. The friction shoes will now have practically nofriction grip upon the blade and are movable freely thereon owing to thereduced thickness of the section 2' of the blade and owing. also, to thefact that the tension of the spring 35 is taken of the shoes for thereason that the nuts 40 upon the arms 25 of the strap are in engagementwith the bearings 32 on the inner sides of the ends of the saddle. Inother words, the adaptation of the parts is such that the saddle withthe spring 35 bearing against it will be lifted away from its bearingupon the shoe 4 and rest entirely upon the nuts 40 on the arms of thestrap, relieving accordingly the friction shoes from all pressureexerted by the spring 35. The shoes are accordingly in a position tomove freely along the blade even though they are occupying an o erativeposition as above defined with relation to their carrier. I

Assuming now that the o eration of the vehicle to which the spring isattachedhas tended to compress the vehicle spring: Thereupon thefriction blade will move downwardly through the nest of friction shoes.As this actlon continues a friction grip of the shoes upon the bladewill gradually take place owing to the gradual thickening of the section2' of the blade. A point will at length be reached where the resistanceoccasioned by the friction grip of the shoes against the blade willovercome the tension of the spring 56. In other words, the blade willmove downwardly to a position where it will carry the shoes with it. Atsuch moment the shoes will be moved downwardly into an inoperativeposition as before defined and all the parts assume a ositionsubstantially as shown in Fig. 4 w ich continues to the end of themovement and full compression of the vehicle spring with which thedevice is associated. It may be noted, however, that although the shoesare in an inoperative position, yet even under such circumstances theadjustment of the parts is preferably such that the shoes will have someslight friction grip upon the blades owing to the thickening of thesection 2' of the blade but not enough to prevent a free and easycompression of the vehicle spring.

Assuming now that the vehicle sprin has become fully compressed and thetendency is for the sprin to rebound with the usual back lash, whic isthe difiiculty especially to be avoided: As the vehicle sprln reboundsthe friction blade will he suddenly drawn upward carryin the frictionshoes with it owing to the frictional engagement of the shoes with theblade. Thereupon the shoes will be moved into an operative position andthe U-sha ed strap into its acute angular position. 11 this connectionit may be said that the strap will readily assume its acute angularposition owing to the fact that the saddle will pivot or turn upon thebearing 28 of the shoe 4. The parts will now have assumed a positionsubstantially as shown in Fig. 5. The changed position of the rollerbearings will have compressed the spring 35 with the resultant effect offorcing the shoes with a very high degree of pressure against the bladewhich immediately acts as a brake or 'p against any tendency of thevehicle spring to back lash.

he pressure upon the shoes at this time is occasioned not only by theturned position of the roller bearings but also in no small art by theacute angular position of the -shaped strap. Although a very sudden andintense pressure is exerted upon the shoes at this time yet there is nopossibility of slippage for the reason that the turned position of theroller bearings is well within the critical angle. The application ofpressure though sudden is not an impulsive action but a gradual thoughquick action owing to the nature of the bearings, the pressure graduallyreaching a maximum when the friction shoes are brought into their fullyoperative Fig. 5.

As the retraction of the spring continues the friction blade will bedrawn out of the nest of shoes. The pressure of the shoes, however,against the blades is gradu'ally becoming less and less as the section 2of the olade decreases in thickness, the action corresponding relativelywith the decreasing reactive force of the vehicle spring until the imewhen the vehicle spring resumes its normal position and the operativeparts of the device their referred to.

Having thus fully described my invention, I claim and desire to secureby Letters Patent of the United States 1. In a shock absorber, thecombination comprising a friction blade, a friction member in contactwith said blade, a carrier for the friction member retained tocoiiperate with said blade in the support of said friction member and inrelation to which said friction member is retained to have a limitedendwise movement, a compression member interposed between said frictionmember and said carrier, said friction and compression memberspresenting surfaces c ooperating with one another whereby said normalpositions as above compression member may have a determinate rollingcontact with said friction amber and simultaneously with the rolling 'iaid compression member said members be displaced laterally in relationto one another, and means whereby said compression member may beretained to have a deterinate rolling contact with the surface of ddfriction member and a lateral displacement of said members be efiectedupon the endwise displacement of said friction memher and said carrierwith relation to one another.

2. In a shock. absorber, the combination comprising a friction blade, afriction memer in contact with sa d blade, :1 carrier for position asshown in,

the friction member retained to 006 crate with said blade in the supportof sai friction member and in relation to which said friction member isretained to have a limited endwise movement, a compression memberinterposed between said friction member and said carrier, said carrierand compression member presenting surfaces coiiperating with one anotherwhereby said compression member may have a determinate rolllng contactwith said carrier and simultaneously with the rolling of said comression member said friction member be isplaced laterally in relation tosaid carrier, and means whereby said compression member may be retainedto have s determinate rolling contact with the surface of said carrierand a lateral displacement of said friction member be effected upon theendwise displacement of said friction member and said carrier withrelation to one another.

3. In a shock absorber, the combination comprising a friction blade, afriction member in contact with said blade, a carrier for the frictionmember retained to cod erate with said blade in the support of saifriction member and in relation to which said friction member isretained to have a limited endwise movement, a compression memberinterposed between said friction member and said carrier, said frictionmember and said carrier both presenting surfaces cooperating withsurfaces presented by said compression member whereby said compressionmember may have a determinate rolling contact with both said frictionmember and said carrier and simultaneouslg' with the rolling of saidcompression mem er said friction member be displaced laterally inrelation to said carrier, and means whereby said compression member maybe retained to have a determinate rolling contact with both said friction member and said carrier and. a lateral displacement of saidfriction member be effected upon the endwise displacement of saidfriction member and said carrier with relation to one another.

4. In a shock absorber, the combination comprising a friction blade,friction shoes arranged to engage said blade on opposite sides thereofand combined to be movable in unison, a carrier for the shoes withrelation to which said shoes are confined to have a limited endwisemovement, a stra passed around the back of said carrier and mounted toturn ivotally thereon with arms extending by said blade and shoes oneither side thereof, and means for yieldingly retaining under tensionand otherwise pivotally supporting the outer ends of said arms.

5. In a shock absorber, the combination comprising a friction blade,friction shoes arranged to engage said blade on op osite sides thereofand combined to be mova le in un on, a carrier for the shoes withrelation to which said shoes are confined to have a limited endwisemovement, bearings interposed between said carrier and one of saidshoes, a strap passed around said carrier and mounted to turn thereonwith its arms extending by said shoes and blade on either side thereof,and means for yieldingly re taining under tension and otherwisepivotally supporting the outer ends of said arms.

6. In a shock absorber, the combination comprising a friction blade,friction shoes arranged to engage said blade on opposite sides thereof,a carrier for the shoes with relation to which said shoes are retainedto have a limited endwise movement, means whereby draft may be exertedlaterall upon said carrier and pressure against sai shoes upon thelateral displacement of said carrier away from one of said shoes, andmeans inte osed between said carrier and said one of sai shoes forchanging the spaced relationship of said carrier and shoe upon theendwise displacement of said shoes and carrier with relation to oneanother.

7 In a shock absorber, the combination comprising a friction blade,friction shoes, a carrier for'the shoes with relation to which saidshoes are confined to have a limited longitudinal movement, a strappassed around the back of said carrier and mounted to turn pivotallythereon with arms extending by said blade and shoes on either sidethereof, and means for yieldingly retaining the outer ends of said armsto exert a tensional draw thereon for exerting pressure against saidshoes to have frictional engagement with said blade and comprising inpart a member having a pivotal bearing on one of said shoes whereb saidstrap may turn upon said carrier and the pressure exerted upon saidshoes become changed as the position of said shoes is changed in theirrelation to the carrier.

8. In a shock absorber, the combination comprising a friction blade,friction shoes, :3, carrier for the shoes with relation to which saidshoes are confined to have a limited longitudinal movement, a strappassed around the back of said carr er and mounted to turn pivotallythereon with arms extending by said blade and shoes on either sidethereof, and means for yieldingly retainin the outer ends of said armswhereby sai strap may turn relatively to said shoes as the position ofsaid shoes becomes changed with relation to the carrier, said meanscomprising in part a member mounted to turn, upon one of said shoes, aspring beari against said member and other arts retamed b the ends ofthe arms of t e strap to have airing against said spring.

9. Ina shoe a sorber, the combination comprisin a friction blade,friction shoes, a carrier or the shoes with relation to which said shoesare confined to have a limited longitudinal movement, a stra passedaround the back of said carrier an mounted to turn pivotally thereonwith arms extending by said blade and shoes on either side thereof,means for yieldingly retaining the outer ends of said arms, said meansconsisting in part of a spring, and a saddle against which said springas bearin and which is mounted to turn upon one 0 said shoes.

10. In a shock absorber, the combination comprising a friction blade,friction shoes, a carrier for the shoes with relation to which saidshoes are confined to have a limited lon 'tudinal movement, means forretaining sai carrier to coiiperate with said blade in the support ofsaid shoes, said means com prising 1n part a resilient member by whichpressure may be applied to said shoes to rictionally grip said blade,means interposed between said carrier and one of said shoes to changethe space relationship of said carrier and shoes as the relati 'eposition of said shoe becomes changed 1 )ngitudinally with relation tosaid carrier for varying the application of pressure to said shoes, andother means by' which the application of pressure exerted by saidresilient member may be taken of! said shoes.

11. In a shock absorber, the combination comprisin a friction blade,friction shoes, a carrier or the shoes with relation to which said shoesare confined to have a limited longitudinal movement, a strap passedaround the back of said carrier and mounted to turn pivotall thereonwith arms extending by said blade and shoes on either side thereof,means for yieldingly retaining said arms comprising in art a spring bywhich pressure may be app ied to said shoes to frictionally grip saidblade, a saddle interposed between said arms of the strap and againstwhich said spring has bearing, said saddle having bearing against one ofsail shoes, and adjustable members arranged upon said arms to havebearin against said saddle, substantially as descn ed.

12. In a shock absorber, the combination comprising a friction blade,friction shoes arranged o engage said blade on opposite sides thereof, acarrier for the shoes with relation to which and to said blade saidshoes are confined to have a mited longitudinal movement, a strap passedaround the back of said carrier and mounted to turn pivotally thereonwith arms extending bly said blade and shoes on either side t ereof,means whereby said strap may be yieldingly maintained to exert draftupon. said carrier and pressure against said shoes to have frictional enagement with said blade and whereby, a so, said strap may turn upon saidcarrier and the pressure exerted upon said shoes become chan ed as theposition of said shoes is changed engitudinally in their relation to thecarrier, and and pressure against said shoes to have other meansassisting in such variance of frictional engagement with said blade andpressure interposed between the carrier and whereby, also, said strapmay turn upon one of said shoes and cooperating therewith said carrierand the pressure exerted upon 5 to change the space relationship of thecarsaid shoes become chan d as the position rier and shoe as therelative position of the of said shoes is change longitudinally in shoesbecomes changed longitudinally to the their relation to the carrier,roller bearings carrier as aforesald. interposed between the carrier andone of 13. In a shock absorber, the combination said shoes andcooperating therewith to 10 comprising a friction blade, friction shoeschange the space relationship of said cararranged to engage said bladeon opposite rier and shoe as the relative position of said sidesthereof, a carrier for the shoes with shoes becomes changedlongitudinally with relation to which and to said blade said relation tothe carrier, and a resilient memshoes are confined to have a limitedlongituber interposed between said one of the shoes 1 dinal movement, astrap passed around the and the carrier for yieldingly maintaining backof said carrier and mounted to turn said shoes and other shoes with itin 0. norpivotally thereon with arms extending b mal position in theirrelation longitudinally said bladeand shoes on either side thereof: tothe carrier. means whereby said stra may be yieldingly 20 maintained toexert draft upon said earner JAMES S. LAN G.

